The present invention relates to a process for metering, shaping and optionally packaging multi-layered portions of spreadable food products and to an apparatus for carrying out the process.
Portions of spreadable food products such as, for example, creamy processed cheeses are usually produced by pouring measured amounts of spread, under hot conditions, from a nozzle into shells of the desired shape with raised edges, fitting a cover, folding back and fixing the edges and removing the packed portions. It is difficult to meter the portions exactly and attempts to shape them prior to moulding have been abandoned owing to their viscous and sticky consistency. The problem is aggravated if they are arranged as distinct layers, by combining spreads which have quite different visual and organoleptic properties but which complement each other, to give the portions a contrasting stratified appearance, significantly improving the organoleptic sensations over those induced by the same products premixed in the portion.
According to the patent CH No. 538,814 and the published patent application FR No. 2,310,084, for example, portions of processed cheese are given a marbled appearance by injecting additives or a second spread with a different flavour or colour into a stream of first spread, upstream of the nozzle discharging the product into the shells. These processes do not produce the desired stratified portions.
Another method described in published patent application FR No. 2,475,361 proposes that the retentate from ultrafiltration of milk, before addition of rennet, be transformed into multi-layered cheeses by successively moulding each liquid layer on the previous, already coagulated layer or by mixing retentates of differing density which separate in the moulds by gravity and subsequently coagulate. This method can be applied only to cream cheeses and, moreover, produces only horizontal layers, the stratified appearance not being visible immediately after the packaging is opened.
Another process illustrated in U.S. Pat. No. 3,359,925 permits production of blocks of two-flavoured ice-cream arranged chequer-wise, whereas, according to U.S. Pat. No. 3,991,217, some pots are filled with several layers of different flavoured ice-creams arranged in vertical slices. According to these patents, at least two ice-creams of different flavour are transferred into a shaping chamber consisting of several compartments separated by thin walls, in which the layers are formed individually one beside the other and are extruded simultaneously into a packaging containter by means of pistons. These processes would not allow the desired multi-layered portions to be metered and shaped from spreadable products and, in particular, from processed cheeses as they would very quickly adhere to the pistons.